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When it is warm check to see if the compressor is running. Could be that you have a blockage in the system and the pressure is building up that the high side pressure cutout is kicking in, or the lowside is low and the lowside pressure cutout is kicking in. The only way to determine the problem is to connect a set of gauges to the system and find out what the pressure readings are.

Next time it happens to me on the freeway I will test the theory by shutting off the Ac and allowing it to defrost. Then turn back on again in a few minutes, if it blows cold after this then it may well be that its true, the line is freezing up somewhere.

This is exactly what happens to my X5 50. Crank the fan on high and it sounds like its blowing really hard but no air (or very little) is coming out of the dash vents. The air is warm and humid. Turn it off for 15-20 minutes and it'll thaw out and work fine.....until it freezes up again.

This is exactly what happens to my X5 50. Crank the fan on high and it sounds like its blowing really hard but no air (or very little) is coming out of the dash vents. The air is warm and humid. Turn it off for 15-20 minutes and it'll thaw out and work fine.....until it freezes up again.

Has anyone found a fix to this? I have 03 x5 4.4i and am having the same problem. Air blows great highway, but after a while the front vents stop, but back still works just fine. No matter how I adjust the settings it will not come back on. After I get out for a few minutes when I start the car back up, it works again. What could it be?